Review Question - QID 219807

The patient has hypothyroidism based on her very elevated TSH (normal 0.5-5.0 mU/) and low free T4 (normal 0.7 to 1.9ng/dL), which has been shown to be an independent risk factor for the development of PJI in the setting of total elbow arthroplasty (TEA).

The overall lifetime revision rate of TEA is ~ 13%, with the most significant risk factors for failure being a history of smoking, the presence of medical comorbidities (rheumatoid arthritis, hypothyroidism, uncontrolled diabetes, iron deficiency anemia, and obesity), the use of either highly constrained or non-constrained systems, and non-compliance with activity restrictions. In terms of PJI, there are no definitive tests to reliably diagnose periprosthetic elbow infection, and there are no documented acceptable synovial WBC counts reliably indicative of infection after aspiration, meaning that a high clinical suspicion and knowledge of risk factors is necessary for diagnosis and timely treatment. As with PJI in other joints, treatment is tailored to the individual and timeline of infection, but most frequently involves a two-stage procedure with debridement, implant removal, and placement of an antibiotic spacer followed by a period of IV antibiotics and subsequent re-implantation.

Goyal et al. reviewed the management of periprosthetic joint infection in total elbow arthroplasty. The authors note that despite the potential morbidity associated with TEA PJI, evidence is limited regarding an optimal treatment algorithm. Irrigation and debridement is associated with a relatively high risk of infection recurrence, especially in chronic infections, while two-stage revision offers a lower recurrence risk, although there is a 25% chance of not completing the second stage. They conclude that further multicenter prospective studies and a retrospective review of registry data focusing on different treatment algorithms, prevention strategies, and functional outcomes would be helpful to elucidate the ideal management of elbow PJI.

Pham et al. reviewed the outcomes of the Coonrad-Morrey total elbow arthroplasty for patients with rheumatoid arthritis. The authors reviewed 54 prostheses over an average of 7 years and found that the survival rate was 97% at 5 years and 85% at 10 years, with radiolucencies being observed in 6 cases around the humeral component and in 6 cases around the ulnar component at mean follow-up. Overall, there were 14 complications (26%) and revisions were performed in 6 of them (11%). They concluded that the Coonrad-Morrey prosthesis provides satisfactory results at mean follow-up, though the rate of complications remains high even if the rate of implant revision stayed low.

Somerson et al. reviewed the risk factors associated with periprosthetic joint infection after total elbow arthroplasty. The authors performed a multivariate analysis on a single database of TEA patients from 2003 to 2012 in New York State and found that in 1452 patients, significant risk factors for PJI included hypothyroidism [odds ratio (OR) = 2.04; p = 0.045], tobacco use disorder (OR = 3.39; p = 0.003), and rheumatoid arthritis (OR = 3.31; p < 0.001). They concluded that pre-operative optimization of thyroid function, smoking cessation, and management of rheumatoid disease should be considered in surgical candidates for TEA.

Figure A represents AP and lateral radiographs of a post-operative TEA with significant loosening of both humeral and ulnar components, concerning for likely chronic infection.

Incorrect Answers:
Answers 1 and 3: Female gender and Nordic heritage have not been identified as independent risk factors of infection in TEA.
Answer 4: An elevated HbA1c is indicative of poorly controlled diabetes and would be a risk factor for infection, but this patient's A1c is < 6.0%
Answer 5: Though rheumatoid arthritis is a risk factor for infection in TEA, a positive RF is not specific for rheumatoid arthritis, especially in the setting of this patient's negative anti-CCP, which indicates that she likely does not have RA.